Humidifiers are known for humidifying air passing through ventilating devices. One such humidifier which is particularly effective is that described in U.S. Pat. No. 4,225,542, the content whereof is incorporated herein by reference. Generally that humidifier comprises means for defining a main reservoir adapted for containing water, a water supply tube adapted to be coupled to a source of water under pressure for conducting water to the main reservoir, inlet float means for allowing flow of water through the supply tube when water in the main reservoir is below a first predetermined level and for normally stopping flow through the supply tube when water in the main reservoir reaches the first predetermined level; a wick having a bottom end portion projecting into the main reservoir and an opposite end portion projecting from the main reservoir; and means for directing a flow of air under greater than atmospheric pressure over the wick so that water vapor evaporating from the wick will humidify the air.
While such humidifiers normally function well, the spectre remains that if the inlet float means in such a humidifier malfunctions for any reason (e.g., such as improper assembly of the humidifier or damage to its parts caused by handling), water could rise above the first predetermined level, flood the humidifier, enter the air flow through the humidifier in its liquid state, and be carried into the breathing passageways of a patient (often an infant) connected to a ventilator in which the humidifier is used.